Bell piston pump



United States Patenti() l BELL'PISTON PUMP John B. McGay, Tulsa, Okla.

Application September 6, 1956, Serial No. 608,374

Claims. (Cl. 103-46) 4-Patented. Dec. 29,1959

- suddenly,vvv but the column oftluid tends to con-timxeA its upwardmovement,l thus vcreatinga vacuum-at the head Y ofv the bell piston anddrawing in well uid through the standing or bottom hole valve. Thus, thepresentinvenytiongprovidesa novel bottom hole pumping apparatus which issimple and eilicient in operation, and economical and durable inconstruction. Y

It isA an important object of this invention to provide a novel pumpingapparatusv for a well bore whereby abell piston is disposed on thelowerrnost portion of the well tubing yfor reciprocation by uid pressuredifferentials, thereby eliminating the use of sucker lrods, and-thelike,

v 4extending downwardly throughout the length ofthe-well bore.

It is -another object ofv this invention to provide al novel bottom holepumping apparatus for a well bore wherein theypump may be easily andsimply charged with atmospheric pressure prior to pumping operation ofthe appathrough the well bore` for production thereof `at the' surtaceof-I the ground. These pumps are often rod'actuated g-pumps'wherein thepumping memberis-disposedat-,the @bottom of -the well bore and Iisactuated from the lsurface by `means of af string of rods extendingdownwardlyin rfthef well bore. The well borev is usually crooked ordivergestroma true vertical disposition as ityextends downwardly in theearth. IIt will be-apparentthat-this econdition will be greatlyexaggerated in Yexcessively Ydeep -well bores. yThe substantiallystraight rod membersfextending through the crooked'boreihole oftenrub-against the well casing or well bore upon recip-rocation thereinfandtbecome disjointed, worn out, and, therefore,vineffec tive foractuation of the'pump. Furthermore,- as the depth of'a well boreincreases,--itbecomes yincreasingly dillicult to raise the uidtherein-by rod actuatedbottom..

fholepump tothe surface offthe well fo-r production.

' `Thus, theoil industry increases thedrilling -of deep --well =bores,`the problem jof actuating the-bottom hole .pump fromwthersurface offvthe-well to liftwthe-welldl-uid is greatly increased.

T he present inventionv contemplates a novel bottom hole.Jpump-particularly -designed-and constructed to=-faciltate.v-thefpumping of fluid fromthe deep'fwellbore. 'Abell fpiston operatingin a'rather long `cylinder provided at the bottom of the bore. When thiscylinder,atta'ched to the end o-fv the well tubing, -isZlower'edinto\thefwell"the whole of; the cylinder andtubing containsairat atmos- .-pheric.pressure, and when the tubing is'primedbyffilliing `ratus.

It is'still another object of this invention to provide a bottom 4holepumping apparatus for deep well bores wherein the pumping member isactuated by means of y auroit-set piston having a relatively shortstroke to provide. pressure on the upstrokethereof so that the novelpump may be utilized with the normal well pumping jack members.

#It is a'further object of this invention to provide abot- Vtom.V holepumping apparatus wherein `a quick opening lvalve is utilized to relievethe head pressure in the tubing yat the instant required for the mostefficienty operation of the pumping unit tov provide a snapping actionfor-the trate my invention.

.In the drawings:

Figure-.1 is a broken sectional elevationallview-of a Abottom holek pumpvembodying the-invention disposed within awell bore, anddepictingthepumpin-onepositionof operation.

Eigure 2 Visa similar View toFigfl with the 'pump in another position ofoperation.

A Referring tothe drawings-in detail,y a string of tubing 410 Vislongitudinally disposedwithin a Well bore 12 inf-'any well known mannersuch that the lowermost portion. of

-^ the tubing extends downwardly into -rcommunioation'with Asuitablehfoot jvalve member orA standing valve 14-is p'rovidedatthe-Iflower end 161of-the tubing -10^for=directin`guid 'into it with fluidfrom the top-of the well, the air inthecylinader. is compressed into the(space inside the bell piston,

thus creating a high vpressureinsi'tle the bellfpistonV withv-out thenecessity of pre-charging thefairf-chamberf'with -vhigh pressure air.The bell piston is-reciprocatedin-the cylinderby changes in iluid.pressure in the tubing, which .changes in pressure are-createdby thereciprocation of a rpiston member near the -surfacefof the-ground.

,quick opening toggle'valve is provided at the 'surface Aof theywell'for discharging the Well il'uid from-thetubing. -When the pistonmember at theA surface has driven/the `uid downward in the tubing,thusncompressing the air4 *wheuithebelll piston reaches thelend ofitsitravelitlstopsthe'tubingfr'om the oil reservoir inthe annularspaceA17. ,-A-pumpingunit, generally indicated at 18, isfseeuredffbelow'the'foot valve V14 in substantially'longitudinalalignfmentwth thetubing 10by means of aV suitable-'sleeve member 20. The pumping unit18-compris`es fa "cylindrical housing member. 22 having an aperture 24at the top thereof in communication with the tubing 10 through ffm'ost'end of'thecylinder22. -An air :bell piston* mem- "'helical'spring"member" 28 having oneV end anchored on --the 5endme'tnber- 21supportsthe bell piston 26 andconfsta'ntly urges the piston upwardlylwithin the cylinder'. 22.

Tl'iespring rnemberj 28 is so designed to provideonly a "slight vornegligible force 'on the piston Zofin orderlthat `reciprocaton of vthepiston within the cylinder E'dii-ring fthe operation-ot the pump 18Wil1be determined "entirely by the iluid pressure differentials actingthereon as will be hereinafter set forth.

The piston head portion 29 of the bell piston 26 is provided with aplurality of suction cup members 30 for precluding the tlow of fluidaround the piston head. A resilient annular ring member 32 is disposedat the top of the piston head 29 to provide a bumper or cushioningaction for the piston 26 during an upward movement thereof into contactwith the shoulder 25. A threaded insert member 34 having a longitudinalbore or passageway 36 extending therethrough is threadedly securedwithin the piston head 29. A circumferential flange member 37 isprovided on the threaded insert member 34 for retaining the ring member32 securely in position on the piston head 29. The piston head isprovided with a threaded' bore 38 for receiving the insert member 34.The threaded bore 38 is of a greater length than the insert member 34,as clearly shown in the drawings, such that a chamber 39 is provided incommunication with the longitudinal bore 36 of the insert member 34. Aradial passageway 40 extends outwardly from the chamber 39 to providecommunication between the chamber 39 and the annular space 42 betweenthe piston 26 and the cylinder 22 for a purpose as will be hereinafterset forth.

The well bore 12 is enlarged at 44 near the surface of the earth toreceive a cylinder 46 adjacent the well tubing string 10. The cylinder46 is open at the lower end 48 thereof and the upper end is incommunication with the well tubing at a port 49. A piston member 50 isreciprocally disposed with the open cylinder 46, and is verticallyreciprocated therein by means of a polished rod 52 extending upwardlytherefrom through a suitable stutllng box member 54. The polished rod 52is actuated or vertically reciprocated in any well known manner by meansof a suitable well jack apparatus 56 and suitable actuator 57. It willbe apparent that iluid pressure iluctuations within the open cylinder 46created by reciprocation of the piston t) therein will be communicatedthrough the port 49 to the interior of tubing 10 and downwardlytherethrough to the pumping unit 18.

A port 58 (Fig. 2) is provided in communication with the well tubing toprovide a seat for a suitable quick opening toggle valve member 60. Wellfluid from the well tubing 10 is discharged through the port 58 forstorage, or the like, as determined by the open or closed position ofthe toggle valve 60, as will be hereinafter set forth. The valve 60 isconnected to the well jack 56 by means of a suitable bell crank ortoggle mechanism 62 which is pivotally secured to .a connecting rodmember 63. A pair of spaced stop members 64 and 65 are provided on theconnecting rod 63 for cooperation with a recessed flange member 67provided on the pump jack 56 for Contact thereby to alternately open andclose the valve 60. It will be apparent that the valve 60 is open duringthe downstroke of the jack 56, as shown in Fig. 2, and similarly thevalve is closed during the upstroke thereof, as shown in Fig. l. Theoperation of the lever arm members 62 by the rod 63 provides for aquickv release of the valve 60 upon opening thereof, and securely closesthe valve 60 adjacent the seat 58 as the well jack 56 is operated.

Operation The tubing string 10 is interted in the well bore 12 in theusual manner (not shown) with the pumping unit 18 secured tothe lowerend thereof. The pumping unit 13 and the tubing 10 are illled withnormal atmospheric air upon being disposed within the well bore, and thenormal action of the helical spring 28 will urge the bell piston 26upwardly in the cylinder 22 into contact with the shoulder 25, as shownin Fig. 2. Priming fluid (indicated at 66 in Fig. l) is introduced intothe tubing 10 through the port 58 and open valve 60 in any suitable wellknown manner. The priming fluid ows downwardly by gravity through thetubing l@ and the sleeve 20 into contact with the piston head member 29.The fluid is sealed from a downwardly flow around the piston head by thesuction cups 30, and will, therefore, pass through the orifice 38 intothe small chamber 39 where it is directed through the radial passageway40 into the annular space 42. The priming fluid collects within thechamber 23 of the cylinder 22 and rises upwardly therein to seal olf thelower end of the piston 26, as shown in Fig. 1. The accumulating iluid66 raises within the bell piston and compresses the air present underthe piston head 29. During this priming operation, the static head ofthe iluid in the tubing 10 may overcome the action of the spring 28 andmove the bell piston 26 downwardly slightly within the cylinder 22. Ifthis occurs, however, the spring will slowly move the piston upwardly toa position adjacent the shoulder 2S when the pressure in the chamber 23becomes equal to the pressure at the lower end 16 of the tubing 10. Theair under the piston head 29 is then in a compressed condition and thepressure thereof is equal to the static head of the fluid in the tubing10. The pump 18 is now ready for the producing operation. As anadditional downward force is applied to the top of the fluid within thetubing 10, the iluid column (not shown) is forced downwardly therein tomove the bell piston 26 downwardly and further compress the air underthe piston head. When the additional force acting on the top of theiluid column is removed or released, the compressed air under the bellpiston 26 expands and causes the piston to move rapidly upward until thebumper member 32 seats against the shoulder 25. The upward movement ofthe piston 26 imparts an upward velocity to the fluid column thereabovewithin the tubing 10. The piston 26 is suddenly stopped in its upwardmovement when it strikes the shoulder 25, but the tluid column continuesto move upwardly in the tubing 10 due to the initial velocity and massof the column, thereby creating a vacuum at the lower end 16 of thetubing 10. This lowered pressure, or vacuum, created in the proximity ofthe foot valve 14 is substantially less than the fluid pressure presentin the annulus 17. Thus, the valve 14 is opened by the pressuredifferential acting thereon, as shown in Fig. 2, to permit the wellfluid present in the well bore 12 to enter the end 16 of the tubing 10and replace the iluid being displaced and discharged from the tubing 10.

It will be apparent that a continuous repetition of the alternateapplication and removal of force on the top of the iluid column in thewell tubing 10 will lift the well fluid upwardly through the foot valve14 and through the tubing 10 for discharge at the surface thereofthrough the valve 60. The off-set piston 50 is provided in order tocreate this fluctuating pressure within the tubing. The piston member 50is normally at the bottom of its stroke, as shown in Fig. 2, at thestart of the pumping operation. As the piston 50 is moved upward withinthe open cylinder 46 by operation of the well jack 56, the tluidpressure above the piston 50 is forced through the port 49 into thetubing 10. The toggle valve 60 remains closed as the piston 50 is movingupward on the power stroke thereof. Therefore, the lluid pressure mustmove downwardly within the tubing to provide the additional force on thetop of the fluid disposed within the tubing 10 for actuation of thepumping unit 1S as hereinbefore set forth. At the upper limit of thepower stroke of the piston 50, the well jack contacts the stop member 64to trip the lever arm mechanism 62 for releasing of the toggle valve 60.The fluid pressure present at the top of the tubing 10 adjacent thevalve 60 quickly snaps the released valve 60 to a full open position fordischarge of the well iluid from the tubing through the conduit 68 forstorage in a stock tank 70, or the like. The release of fluid pressurefrom the tubing 10 through the valve 60 naturally decreases the downwardforce on the bell piston 26, thereby permitting the compressed air underthe bell piston to rapidly expand. The simultaneous exa v pension/of thecompressedair. andthe releas'eof'lthlluid Y pressure .from ythe tubingAprovidesvan increased .momentumffor the upwardzmovement ofthebellzpiston to :im- :part-anincreased velocity for the upwardimovement'of-the fluid column thereabove. Thus,.the fluidf column n will continueits upward movementafter the ybellpiston has beensuddenly stopped bycontact ywiththe-shoulder 25, as hereinbefore set forth, toicreate thevacuumaatthe slowerl end 16 ofthe tubing 10.

l:of thevalve will.. drop Vthe valve toward the ;seat."'58. Si-

multaneously the pump jack 56 will contact the second stop member 65 toactuate the linkage mechanism 62 4for closing of the valve securelyadjacent the valve seat y 58. Thus, the reciprocation of the piston 50by the well jack 56 intermittently provides additional pressure withinthe tubing for actuation of the pumping unit 18 to lift the well fluidfrom the bore 12 to the surface of the earth. The strokes of the pumpjack 56 are properly timed to reciprocate the piston 50 for the mostefficient operation of the pumping unit 18 as hereinbefore set forth.

From the foregoing, it will be apparent that the present inventionprovides a novel bottom hole pump for well bores wherein a bell pistonis disposed at the lower end of the well tubing. The bell piston andtubing are charged with normal atmospheric air prior to installationthereof within the well bore, thereby eliminating pre-charging of thepump with compressed air, or the like. Fluid pressure differentialsacting on the iluid column in the tubing reciprocates the bell piston.An upward movement of the bell piston imparts an upward velocity to thefluid column thereabove for lifting thereof toward the surface of theearth. The sudden stopping of the upward movement of the bell pistoncreates a vacuum at the lower end of the well tubing whereby the welllluid in the bore is sucked into the tubing to enter the fluid columnand is lifted to the surface therewith. The reciprocation of the off-setpiston member provides the pressure differentials within the tubing foractuation of the bottom hole bell piston. The timing of the olf-setpiston is adjusted for opening of the surface toggle valve at exactlythe proper moment for discharging the well fluid from the tubing forrelease of the fluid pressure on the bell piston, and similarly, toclose the valve at the instant the flow from the well ceases. Thecontinuous reciprocation or repetition of the cycle of the olf-setpiston provides for an eflicient and economical production of the wellfluid from the well bore.

Changes may be made in the combination and arrangement of parts asheretofore set forth in the specification and shown in the drawings, itbeing understood that any modification in the precise embodiment of theinvention may be made within the scope of the following claims withoutdeparting from the spirit of the invention.

I claim:

1. A well pumping apparatus comprising a tubing string extendingdownwardly in a well bore, a fluid column in the tubing, a fluidpressure responsive means disposed at the lower end of the tubingcomprising a cylinder member in communication with the tubing, a bellpiston reciprocally disposed within the cylinder, a chamber providedunder the piston, means providing communication between the tubing andthe chamber to direct iluid from Atheiluid column to the chamber forcompressing the air therein, means for applying force to the top of thefluid column for moving the bell piston downwardly and furt" ther.compressing the air. thereunder, means for relieving the tluidpressurein vthe ftubing whereby the compressed air. expands to move the bellpiston upwardly, to provide `an-.upward velocity tothe fluid columninthetubing `above'the, piston, valvemeans responsiverto the velocltyofthe fluid column to provide-fordischarge of well-'fluid therefrom. y

. i2. yAfwell pumping apparatus-comprising a -tubingstring l extendingrdownwardly in afwell bore,a iluid column in the. tubing, a fluidpressure responsivemeans disposed at-.thelower endfof the tubingcomprisingva--cylinder member in communication with the tubing,- avbellpiston reciprocally-disposedV within the cylinder, a chamberprovidedunder the-piston, means providing communication between the tubing andthe chamber to direct iluidfrom -:the Ifluid column to the chamber forcompressing the air Atherein,vmeans.for applying force to the ftopof-theriluid column for movingthe bell-'piston downwardly andefurtheiluid pressure in the tubing whereby the compressed air expands to movethe bell piston upwardly, said upward movement imparting an upwardvelocity to the iluid column in the tubing above the piston fordischarge therefrom, means responsive to a vacuum created by upwardmovement of the column to draw well liquid into the tubing forreplacement of the fluid column.

3. A well pumping apparatus in combination with a tubing stringextending downwardly in a well bore into communication with an oilreservoir therein, a lluid column in the tubing, a pressure responsivevalve member provided at the lower end of the tubing, a lluid pressureresponsive means disposed below the valve for moving the lluid columnupwardly in the tubing for discharge therefrom, said means comprising acylinder in communication with the tubing, a bell piston memberreciprocally disposed in the cylinder, a chamber beneath the piston, apassageway providing communication between the tubing and the chamberfor directing lluid to the chamber to compress the air therein, meansfor applying force to the top of the iluid column above the piston formoving the bell piston downwardly and further compressing the airthereunder, means for relieving the pressure of the lluid column in thetubing above the piston whereby the compressed air may expand to movethe bell piston upwardly, said upward movement imparting an upwardvelocity to the lluid column for discharge from the tubing, a shoulderprovided on the cylinder for limiting the upward movement of the bellpiston thereby creating a vacuum in the proximity of the valve member,said vacuum permitting an opening of the valve for discharge of oil fromthe reservoir into the tubing.

4. A well pump apparatus in combination with a tubing string extendingdownwardly in a well bore into communcation with an oil reservoirtherein, a pressure actuated valve member inserted in the tubing stringin the proximity of the oil reservoir, a cylinder disposed below thevalve in communication with the tubing, a bell piston reciprocallydisposed in the cylinder, a piston head provided on the bell piston,means for precluding flow of fluid between the piston head and thecylinder, a chamber beneath the piston head, a passageway for directingfluid into the chamber to compress the air in the chamber, an off-setcylinder member provided adjacent the tubing at the surface of the wellbore and in communication with the tubing, a second piston memberreciprocally disposed in the olf-set cylinder, means for reciprocatingthe second mentioned piston member, said second piston communicating adownward force in the tubing on the upstroke thereof for moving the bellpiston downwardly to further compress the air in the chamber, a quickopening valve member disposed at the surface of the well bore incommunicating with the well tubing, said quick opening valve adapted toopen for discharge of lluid from -the tubing to relieve the pressure ofthe lluid column in the tubing as the second piston member reaches itsupper limit of move' ment, said bell piston moved upwardly by theexpanding of the compressed air upon relief of the pressure in thetubing, said upward movement of the bell piston imparting an upwardvelocity to the fluid column, and means for limiting the upward movementof the bell piston to provide a vacuum adjacent the pressure actuatedvalve for opening thereof to discharge oil from the reservoir into thetubing.

5. A well pumping apparatus in combination with a tubing stringextending downwardly in a well bore having an oil reservoir therein, auid column in the tubing, a bell piston member reciprocally disposed atthe lower end of the tubing, a piston head provided on the bell piston,a chamber beneath the piston head, a passageway for directing fluiddownwardly from the tubing into the cham- 15 ber whereby the air in thechamber is compressed such that the air pressure therein becomes equalto the static head of the fluid column, a standing valve memberinterposed in the tubing string above the bell piston, means forexerting a downward force on the top of the uid column for moving thebell piston downwardly to increase the compression of the air in thechamber, means for relieving the pressure of the fluid column in thetubing for permitting the compressed air to expand thereby moving thebell piston upwardly, said upward movement of the piston imparting anupward velocity of the fluid column for discharging thereof from thetubing, and means for limiting the upward movement of the bell piston toprovide a vacuum adjacent the standing valve for discharge of oil fromthe reservoir into the tubing for replacing the discharged iluid.

References Cited in the le of this patent UNITED STATES PATENTS1,784,706 Phillips Dec. 9, 1930 2,486,617 Soberg Nov. 1, 1949 FOREIGNPATENTS 600,260 France Feb. 3, 1926

